As an interior illumination lamp for a vehicle to be attached to a roof trim of a ceiling in a vehicle room, the interior illumination lamp for a vehicle as disclosed in JP-A-2007-203911 has been known.
Japanese Patent Publication No. JP-A-2007-203911 is discussed below.
<The Interior Illumination Lamp for a Vehicle Disclosed in JP-A-2007-203911>
An object of the interior illumination lamp for a vehicle disclosed in JP-A-2007-203911 is to enhance its assembling workability and to facilitate maintenance works. For this purpose, specifically, in the interior illumination lamp for a vehicle which is composed of a functional part and a decorative part, a locking claw is formed on a side face of a base housing of the decorative part, and an elastically deformable operating panel having a locking part to which the locking claw can be locked is provided in a housing of the functional part. The operating panel is pressed from an inside of a bulb containing room in the decorative part to be elastically deformed, thereby enabling a locked state of the locking part with respect to the locking claw to be released.
<Merit and Demerit of the Interior Illumination Lamp for a Vehicle Disclosed in JP-A-2007-203911>
<<Merit>>
According to the interior illumination lamp for a vehicle disclosed in JP-A-2007-203911, a lamp unit can be reliably assembled to a ceiling panel having a plurality of clamping thicknesses, only by exchanging clamping holders. Therefore, constituent components of the lamp unit and a basic design of a wire harness which is connected to the lamp can be commonly used, and further, specs of the clamping holder can be exchanged according to the ceiling panel to which the lamp unit is to be attached. As the results, there is such a merit that modification of the specs of the components to comply with diversification of the specs of the lamp unit can be restrained to the least extent, and cost for the components can be reduced.
<<Demerit>>
In case where the interior illumination lamp for a vehicle is assembled by a clamp between a roof trim and a lens, utilizing the art in JP-A-2007-203911, it is necessary to mold a whole contact face of the lens to be contacted with the roof trim with high precision, for enhancing an appearance of a mated part of an outer periphery of a decorative surface of the lens to be mated with the roof trim. This incurs an increase of the cost.